The science of material separation has undergone explosive growth as scientists and engineers have taken advantage of physical and chemical phenomena to separate the components of a mixture and developed analytical separation processes for a variety of applications. These developments include chromatographic methods, ultrafiltration techniques, electrophoresis and the like. A specialized branch of separation science comprises gas and liquid chromatographies. Gas chromatography (hereinafter "GC") separates components, solutes, in a complex mixture by partitioning the solute between a gaseous mobile phase and a liquid or solid stationary phase. Gas chromatography is an ideal separation technique for thermally stable, low molecular weight organic compounds between 50-250 daltons in complex mixtures. Since a mobile inert gas is used to carry the solute(s) through the apparatus, many more analytical detectors and detection techniques are amenable to gas chromatography than in liquid column chromatography. On the other hand, liquid chromatography (hereinafter "LC") is the separation of solutes based upon partitioning between two immisible liquid phases, one stationary and the other mobile, or between a liquid mobile phase and a stationary solid phase. High Performance Liquid Chromatography (hereinafter "HPLC") has been developed to decrease the time of analysis over LC and has found wide use as both analytical and preparative separation tools.
One major disadvantage of HPLC and LC in comparison to GC techniques is the limited number of available detectors and detection methodologies, particularly with respect to detection of one or more specific analytes. To overcome this obstacle, a variety of means for combining gas chromatography detectors with HPLC assemblies have been devised. Exemplifying these efforts are the innovations described in U.S. Pat. Nos. 3,835,332; 3,877,875; 3,973,910; 3,996,002; 3,996,003; 3,996,004; 3,996,008; 3,996,009; 4,066,409; and 4,070,155.
Despite such innovations, there remains a recurring series of obstacles, disadvantages, and problems in known apparatus developed in an effort to integrate and combine liquid chromatography systems with gas chromatography detectors. For example, a continuing inability to detect an analyte of interest exists because the liquid solvent carrier is not adequately or effectively separated from the analyte of interest, such that, at the time of detection, there is a concomitant inability to identify and accurately measure the analyte in the sample. Furthermore, the inability to separate the liquid solvent from the analyte prior to detection causes major losses of sensitivity and specificity. It is clear, therefore, that there remains a continuing and recognized need for specific apparatus which is effective and reliable for the separation of at least one analyte of interest from a liquid solvent carrier.